馬哥教育網絡班20期+第4周課程練習
1、復制/etc/skel目錄為/home/tuser1，要求/home/tuser1及其內部文件的屬組和其它用戶均沒有任何訪問權限。
# cp -a /etc/skel /home/tuser1 # chmod -R go-rx /hom/tuser1 實例演示 [root@C664BSLab ~]# cp -a /etc/skel /home/tuser1 [root@C664BSLab ~]# ll -d /home/tuser1 drwxr-xr-x. 2 root root 4096 Jun 27 23:19 /home/tuser1 [root@C664BSLab ~]# chmod -R go-rx /home/tuser1 [root@C664BSLab ~]# ll -d /home/tuser1 drwx------. 2 root root 4096 Jun 27 23:19 /home/tuser1 [root@C664BSLab ~]# ll -a /home/tuser1/ total 20 drwx------. 2 root root 4096 Jun 27 23:19 . drwxr-xr-x. 6 root root 4096 Jul 3 02:45 .. -rw-------. 1 root root 18 May 11 07:21 .bash_logout -rw-------. 1 root root 176 May 11 07:21 .bash_profile -rw-------. 1 root root 124 May 11 07:21 .bashrc
2、編輯/etc/group文件，添加組hadoop。
# echo "hadoop:x:501:" >> /etc/group 實例演示 [root@C664BSLab ~]# tail -1 /etc/group centos:x:500: [root@C664BSLab ~]# echo "hadoop:x:501:" >> /etc/group [root@C664BSLab ~]# tail -1 /etc/group hadoop:x:501:
3、手動編輯/etc/passwd文件新增一行，添加用戶hadoop，其基本組ID為hadoop組的id號；其家目錄為/home/hadoop。
# echo "hadoop:x:501:501::/home/hadoop:/bin/bash" >> /etc/passwd 實例演示 [root@C664BSLab ~]# tail -1 /etc/passwd centos:x:500:500::/home/centos:/bin/bash [root@C664BSLab ~]# echo "hadoop:x:501:501::/home/hadoop:/bin/bash" >> /etc/passwd [root@C664BSLab ~]# tail -1 /etc/passwd hadoop:x:501:501::/home/hadoop:/bin/bash
4、復制/etc/skel目錄為/home/hadoop，要求修改hadoop目錄的屬組和其它用戶沒有任何訪問權限。
# cp -a /etc/skel /home/hadoop # chmod go-rx /home/hadoop 實例演示 [root@C664BSLab ~]# cp -a /etc/skel /home/hadoop [root@C664BSLab ~]# ll -d /home/hadoop drwxr-xr-x. 2 root root 4096 Jun 27 23:19 /home/hadoop [root@C664BSLab ~]# chmod go-rx /home/hadoop [root@C664BSLab ~]# ll -d /home/hadoop drwx------. 2 root root 4096 Jun 27 23:19 /home/hadoop
5、修改/home/hadoop目錄及其內部所有文件的屬主為hadoop，屬組為hadoop。
# chown -R hadoop:hadoop /home/hadoop 實例演示 [root@C664BSLab ~]# chown -R hadoop:hadoop /home/hadoop [root@C664BSLab ~]# ll -d /home/hadoop drwx------. 2 hadoop hadoop 4096 Jun 27 23:19 /home/hadoop
6、顯示/proc/meminfo文件中以大寫或小寫S開頭的行；用兩種方式；
# grep -i "^[s]" /proc/meminfo # grep "^[Ss]" /proc/meminfo 實例演示 [root@C664BSLab ~]# grep -i "^s" /proc/meminfo SwapCached: 0 kB SwapTotal: 2031612 kB SwapFree: 2031612 kB Shmem: 196 kB Slab: 93404 kB SReclaimable: 32680 kB SUnreclaim: 60724 kB [root@C664BSLab ~]# grep "^[Ss]" /proc/meminfo SwapCached: 0 kB SwapTotal: 2031612 kB SwapFree: 2031612 kB Shmem: 196 kB Slab: 93396 kB SReclaimable: 32676 kB SUnreclaim: 60720 kB
7、顯示/etc/passwd文件中其默認shell為非/sbin/nologin的用戶；
# grep -v "/sbin/nologin$" /etc/passwd 實例演示 [root@C664BSLab ~]# grep -v "/sbin/nologin$" /etc/passwd root:x:0:0:root:/root:/bin/bash sync:x:5:0:sync:/sbin:/bin/sync shutdown:x:6:0:shutdown:/sbin:/sbin/shutdown halt:x:7:0:halt:/sbin:/sbin/halt centos:x:500:500::/home/centos:/bin/bash hadoop:x:501:501::/home/hadoop:/bin/bash
8、顯示/etc/passwd文件中其默認shell為/bin/bash的用戶；
# grep "/bin/bash$" /etc/passwd 實例演示 [root@C664BSLab ~]# grep "/bin/bash$" /etc/passwd root:x:0:0:root:/root:/bin/bash centos:x:500:500::/home/centos:/bin/bash hadoop:x:501:501::/home/hadoop:/bin/bash
9、找出/etc/passwd文件中的一位數或兩位數；
# grep -E "\<[0-9]{1,2}\>" /etc/passwd
實例演示
[root@C664BSLab ~]# grep -E "\<[0-9]{1,2}\>" /etc/passwd
root:x:0:0:root:/root:/bin/bash
bin:x:1:1:bin:/bin:/sbin/nologin
daemon:x:2:2:daemon:/sbin:/sbin/nologin
adm:x:3:4:adm:/var/adm:/sbin/nologin
lp:x:4:7:lp:/var/spool/lpd:/sbin/nologin
sync:x:5:0:sync:/sbin:/bin/sync
shutdown:x:6:0:shutdown:/sbin:/sbin/shutdown
halt:x:7:0:halt:/sbin:/sbin/halt
mail:x:8:12:mail:/var/spool/mail:/sbin/nologin
uucp:x:10:14:uucp:/var/spool/uucp:/sbin/nologin
10、顯示/boot/grub/grub.conf中以至少一個空白字符開頭的行；
# grep -E "^[[:space:]]+" /boot/grub/grub.conf 實例演示 [root@C664BSLab ~]# grep -E "^[[:space:]]+" /boot/grub/grub.conf root (hd0,0) kernel /vmlinuz-2.6.32-573.el6.x86_64 ro root=/dev/mapper/vg_c664bslab-lv_root rd_NO_LUKS.UTF-8 rd_NO_MD SYSFONT=latarcyrheb-sun16 crashkernel=auto rd_LVM_LV=vg_c664bslab/lv_swap KEYBOARDTYPE=pc KEYTABLE=us rd_LVM_LV=vg_c664bslab/lv_root rd_NO_DM rhgb quiet initrd /initramfs-2.6.32-573.el6.x86_64.img
11、顯示/etc/rc.d/rc.sysinit文件中以#開頭，后面跟至少一個空白字符，而后又有至少一個非空白字符的行；
# grep -E "^#[[:space:]]+[^[:space:]]+" /etc/rc.d/rc.sysinit 實例演示 [root@C664BSLab ~]# grep -E "^#[[:space:]]+[^[:space:]]+" /etc/rc.d/rc.sysinit # /etc/rc.d/rc.sysinit - run once at boot time # Taken in part from Miquel van Smoorenburg's bcheckrc. # Check SELinux status # Print a text banner. # Only read this once. # Initialize hardware # Set default affinity # Load other user-defined modules # Load modules (for backward compatibility with VARs)
12、打出netstat -tan命令執行結果中以‘LISTEN’，后或跟空白字符結尾的行；
# netstat -tan | grep "LISTEN[[:space:]]*$" 實例演示 [root@C664BSLab ~]# netstat -tan | grep "LISTEN[[:space:]]*$" tcp 0 0 0.0.0.0:39243 0.0.0.0:* LISTEN tcp 0 0 0.0.0.0:111 0.0.0.0:* LISTEN tcp 0 0 0.0.0.0:22 0.0.0.0:* LISTEN tcp 0 0 127.0.0.1:631 0.0.0.0:* LISTEN tcp 0 0 127.0.0.1:25 0.0.0.0:* LISTEN tcp 0 0 :::58845 :::* LISTEN tcp 0 0 :::111 :::* LISTEN tcp 0 0 :::22 :::* LISTEN tcp 0 0 ::1:631 :::* LISTEN tcp 0 0 ::1:25 :::* LISTEN
13、添加用戶bash, testbash, basher, nologin (此一個用戶的shell為/sbin/nologin)，而后找出當前系統上其用戶名和默認shell相同的用戶的信息；
# useradd bash # useradd testbash # useradd basher # useradd -s /sbin/nologin nologin # grep -E "^([[:alpha:]]+\>).*\1$" /etc/passwd 實例演示 [root@C664BSLab ~]# useradd bash [root@C664BSLab ~]# useradd testbash [root@C664BSLab ~]# useradd basher [root@C664BSLab ~]# useradd -s /sbin/nologin nologin [root@C664BSLab ~]# tail -4 /etc/passwd bash:x:502:502::/home/bash:/bin/bash testbash:x:503:503::/home/testbash:/bin/bash basher:x:504:504::/home/basher:/bin/bash nologin:x:505:505::/home/nologin:/sbin/nologin [root@C664BSLab ~]# grep -E "^([[:alpha:]]+\>).*\1$" /etc/passwd sync:x:5:0:sync:/sbin:/bin/sync shutdown:x:6:0:shutdown:/sbin:/sbin/shutdown halt:x:7:0:halt:/sbin:/sbin/halt bash:x:502:502::/home/bash:/bin/bash nologin:x:505:505::/home/nologin:/sbin/nologin
14、顯示/proc/meminfo文件中以大寫或小寫S開頭的行；用三種方式；
# grep -i "^s" /proc/meminfo # grep "^[Ss]" /proc/meminfo # grep -iv "^[a-rt-z]" /proc/meminfo 實例演示 [root@C664BSLab ~]# egrep -i "^s" /proc/meminfo SwapCached: 0 kB SwapTotal: 2031612 kB SwapFree: 2031612 kB Shmem: 196 kB Slab: 93428 kB SReclaimable: 32752 kB SUnreclaim: 60676 kB [root@C664BSLab ~]# egrep "^[Ss]" /proc/meminfo SwapCached: 0 kB SwapTotal: 2031612 kB SwapFree: 2031612 kB Shmem: 196 kB Slab: 93428 kB SReclaimable: 32752 kB SUnreclaim: 60676 kB [root@C664BSLab ~]# egrep -iv "^[a-rt-z]" /proc/meminfo SwapCached: 0 kB SwapTotal: 2031612 kB SwapFree: 2031612 kB Shmem: 196 kB Slab: 93428 kB SReclaimable: 32752 kB SUnreclaim: 60676 kB
15、顯示/etc/passwd文件中其默認shell為非/sbin/nologin的用戶；
# egrep -v "/sbin/nologin$" /etc/passwd 實例演示 [root@C664BSLab ~]# egrep -v "/sbin/nologin$" /etc/passwd root:x:0:0:root:/root:/bin/bash sync:x:5:0:sync:/sbin:/bin/sync shutdown:x:6:0:shutdown:/sbin:/sbin/shutdown halt:x:7:0:halt:/sbin:/sbin/halt centos:x:500:500::/home/centos:/bin/bash hadoop:x:501:501::/home/hadoop:/bin/bash bash:x:502:502::/home/bash:/bin/bash testbash:x:503:503::/home/testbash:/bin/bash basher:x:504:504::/home/basher:/bin/bash
16、顯示/etc/passwd文件中其默認shell為/bin/bash的用戶；
# egrep "/bin/bash$" /etc/passwd 實例演示 [root@C664BSLab ~]# egrep "/bin/bash$" /etc/passwd root:x:0:0:root:/root:/bin/bash centos:x:500:500::/home/centos:/bin/bash hadoop:x:501:501::/home/hadoop:/bin/bash bash:x:502:502::/home/bash:/bin/bash testbash:x:503:503::/home/testbash:/bin/bash basher:x:504:504::/home/basher:/bin/bash
17、找出/etc/passwd文件中的一位數或兩位數；
# egrep "\<[0-9]{1,2}\>" /etc/passwd
實例演示
[root@C664BSLab ~]# egrep "\<[0-9]{1,2}\>" /etc/passwd
root:x:0:0:root:/root:/bin/bash
bin:x:1:1:bin:/bin:/sbin/nologin
daemon:x:2:2:daemon:/sbin:/sbin/nologin
adm:x:3:4:adm:/var/adm:/sbin/nologin
lp:x:4:7:lp:/var/spool/lpd:/sbin/nologin
sync:x:5:0:sync:/sbin:/bin/sync
原創文章，作者：N20-背旅，如若轉載，請注明出處：http://www.www58058.com/21568
寫的很好，排版問題也很棒，加油